Update: ATI AMD Catalyst 12.1 driver for Linux is available, you can check it here.

We have previously seen how to install AMD Catalyst 11.11 under Ubuntu 11.10. In this guide we will also help you install the next version: AMD Catalyst 11.12 for Linux. This new version comes with more new features like the support of AMD OpenGL 4.2 with enhancements in the AMD Eyefinity technology as well as enhancements in AMD Vision Engine Control Center for Dual Graphics.
For smooth installation, it is recommended to uninstall currently availabe Catalyst driver. To do this, use these commands from the terminal: